Core/Shell of Sodium Bicarbonate in composite Shell with Enhanced Thermal Stability

In order to improve the decomposition temperature of the blowing agent SBC (Sodium Bicarbonate), SBC capsulates were prepared by a solvent evaporation method. Microscope micrographs showed that it is difficult for PMMA to cover the entire surface of SBC particles completely. The SBC particles could be completely encapsulated with the existence of surfactants, which could be ascribed to the fact that the surfactant established bonds with SBC and shell materials. Moreover, thermal stability of SBC capsulates were enhanced, that determined using thermal gravimetric analysis (TGA). TGA investigation showed that SBC@10wt% PMMA, and SBC@10wt%PMMA-10wt%GM, an increase of 37℃ and 27℃ is observed in Tonset and Tmax of capsules in comparison with SBC. Correspondingly, the greatest gradient temperature of gas release increased with of 37℃ and 27℃. Based on the results, it can be considered that the encapsulation can improve the thermal stability of SBC, especially, PMMA and GM.